1. Field of the Invention
The present invention relates to a novel pacing wire for use in cardiac surgery, and in particular, to a pacing wire having a slip-joint to facilitate safe and easy removal of the temporary pacing wire upon the patient's post-operative recovery.
2. Description of the Prior Art
After open heart surgery, one or two pairs of temporary pacing wires are typically placed onto the myocardium of the patient and brought out through the patient's chest wall and skin using a Keith needle. Typically, the pacing wires are then sutured to the patient's skin, and the Keith needle is snapped off to allow connection of the pacing wires to a pacemaker. This permits treatment of transient heart block which commonly occurs after open heart surgery. However, the sutures and the pacing wires must then be removed (pulled out through the heart muscle) on the third or fourth postoperative day. The primary complication associated with the removal of the pacing wires is a small incidence of cardiac tamponade, or tear in the heart muscle. The complication is typically manifested in only about 1% of the patients, but the tear to the heart muscle in those cases can be fatal.
FIG. 1 illustrates a standard pacing wire 1 (State of the Art Medical, model M-24). The standard pacing wire 1 (typically 5 cm length) of FIG. 1 is inserted into the myocardium using needle 2 and is insulated by an insulated wire (typically 40 cm length) through the chest wall to outside the patient's body. Once the pacing wire 1 is inserted into the myocardium, the Keith needle 4 is snapped off at snap off point 5, connected to a pacemaker, and sutured to the patient's skin. The pacing wire 1 is removed (pulled) from the heart by pulling the pacing wire 1 at the snap off point 5 at the skin, and the pulling force is directly transmitted to the heart at the bare wire end 1. As just noted, this force and the mechanical energy associated with pulling the bare end of the wire through the heart muscle can result in bleeding, tamponade, and in rare cases, death.
As a result, some surgeons simply cut the wire at the skin to avoid the risk of the infrequent, but potentially devastating complication of cardiac tamponade. Unfortunately, cutting the pacing wire at a point flush with the patient's skin surface is uncomfortable for the patient and leads to a greater risk of infection.
An improved temporary pacing wire is desired which overcomes these difficulties.